Analysis of information sources in references of the Wikipedia article "Clarendon (typeface)" in English language version.
For the record, the Clarendon type of the Besley foundry is indeed the first type actually designed as a 'related bold' – that is, made to harmonize in design and align with the roman types it was set with. It was registered in Britain in 1845...but the idea of a 'bold face' goes back much further. Before the launch of Clarendon type printers picked out words in slab-serifs or any other heavy type. In the 18th century they used 'English' or 'Old English' types, which is why they became known as 'black letter'. John Smith says in his Printer's grammar (London, 1755). 'Black Letter … is sometimes used … to serve for matter which the Author would particularly enforce to the reader.'
For the record, the Clarendon type of the Besley foundry is indeed the first type actually designed as a 'related bold' – that is, made to harmonize in design and align with the roman types it was set with. It was registered in Britain in 1845...but the idea of a 'bold face' goes back much further. Before the launch of Clarendon type printers picked out words in slab-serifs or any other heavy type. In the 18th century they used 'English' or 'Old English' types, which is why they became known as 'black letter'. John Smith says in his Printer's grammar (London, 1755). 'Black Letter … is sometimes used … to serve for matter which the Author would particularly enforce to the reader.'